冷应激对大鼠激素与T淋巴细胞因子的影响

摘要:目的　探讨冷应激对大鼠外周血应激激素及T淋巴细胞因子的影响。方法　将230只SD大鼠分为20℃、4℃、-12℃ 3个环境温度组,每个温度组分非刺激、细菌脂多糖刺激、刀豆素-A刺激亚组,每亚组分1、12、24、48 h 4个时间点观察组;ELISA测定血浆促肾上腺皮质激素,肾上腺素,血管紧张素-2,白介素-2,干扰素-γ,白介素-4和白介素-10。结果　与20℃比较,大鼠4℃和-12℃冷应激血浆促肾上腺皮质激素（1 h,24.48±1.58比51.37±32.32和52.95±3.41;12 h,35.62±5.46比58.12±30.86和73.26±7.14）和肾上腺素（1 h,41.12±2.59比96.45±32.27和110.87±4.66;12 h,73.99±24.28比127.34±77.43和126.36±31.48）、大鼠-12℃冷应激血浆血管紧张素-2（1 h:118.84±31.41比437.13±71.72;12 h,318.08±93.44比440.72±69.43;24 h,247.11±97.79比620.83±67.45;48 h,171.99±67.72比556.38±94.62）以及大鼠冷应激血浆白介素-10（4℃、1 h,21.14±5.27比53.84±25.26;12 h,38.78±14.96比70.02±34.41;24 h,35.65±4.24比57.32±20.70;48 h,37.39±12.31比65.40±32.11;-12℃、1 h,比64.89±13.01,12 h,比68.33±7.31）水平显著升高（P＜0.05）、脂多糖和刀豆素-A刺激机体未改变这种趋势。与20℃比较,血浆IL-2水平在脂多糖刺激下-12℃（48 h,938.18±193.11比675.65±88.14）和刀豆素-A刺激下4℃（1～ 48 h,786.67±134.58比462.34±102.42;1014.07±164.34比472.70±83.88;1194.69±152.03比392.66±41.43;991.56±225.16比501.89±46.65）和-12℃（24 h,比874.58±143.38;48 h比640.24±99.24）、血浆IL-4水平在4℃（12 h,115.58±43.14比62.36±11.94;24 h,90.76±31.85比56.66±20.16;48 h,93.69±37.56比68.09±12.59）和-12℃（12 h,比73.73±11.16）、脂多糖刺激时IL-4水平在4℃（24 h,110.49±51.58比60.13±23.05）以及刀豆素-A刺激时IL-4水平在4℃（1 h,58.25±10.00比32.47±10.43;12 h,125.45±56.12比53.22±9.04;24 h,109.36±15.22比37.93±15.21）和-12℃（12 h,比70.36±9.79）、血浆IFN-γ水平脂多糖刺激时在4℃（12 h,1751.66±618.91比1483.62±390.59）和-12℃（48 h,1829.49±414.15比1184.42±461.01）以及刀豆素-A刺激时在4℃（24 h,1738.92±192.44比1106.13±324.29）显著降低（P＜0.05）。结论　气温骤降可致大鼠应激激素升高以及适应性免疫功能受损。     

Exercise-induced cerebral deoxygenation among untrained trekkers at moderate altitudes.

The pathophysiology of altitude-related disorders in untrained trekkers has not been clarified. In the present study, the effects of workload on cardiovascular parameters and regional cerebral oxygenation were studied in untrained trekkers at altitudes of 2700 m and 3700 m above sea level. We studied 6 males and 4 females at each altitude, and their average ages were 31.3+/-7.1 y at 2700 m and 31.2+/-6.8 y at 3700 m, respectively. The resting values of heart rate and mean blood pressure were not significantly different at 2700 m and 3700 m than at sea level. However, increases in these values after exercise were more prominent at high altitudes (heart rate increase = 51.6% at 2700 m and 70.4% at 3700 m; mean blood pressure increase: 19.0% at 2700 m and 17.2% at 3700 m). In addition, post-exercise blood lactate concentration was significantly higher at 3700 m than at sea level or at 2700 m (i.e., 7.6 mM at 3700 m, 3.8 mM at 2700 m, and 4.17 mM at 0 m, respectively). Exercise induced an acute reduction in the arterial oxygen saturation value (SpO2) at 2700 m and 3700 m (i.e., 11.2% reduction at 2700 m and 9.4% at 3700 m), whereas no changes were observed at sea level. The resting values of regional oxygen saturation (rSO2)--measured by a near infra-red spectrophotometer at sea level, 2700 m, and 3700 m-were nearly identical. Exercise at sea level did not reduce this value. In contrast, we observed a decrease in rSO2 after subjects exercised at 2700 m and 3700 m (i.e., 26.9% at 2700 m and 48.1% at 3700 m, respectively). The rSO2 measured 2 min and 3 min after exercise at 3700 m was significantly higher than the preexercise value. From these observations, we concluded that alterations in cardiovascular parameters were apparent only after an exercise load occurred at approximately 3000 m altitude. Acute reduction in cerebral regional oxygen saturation might be a primary cause of headache and acute mountain sickness among unacclimatized trekkers.     

抗凝血保存温度和时间对血液分析仪测定结果的影响

目的:探讨不同条件下保存的血标本对XS-800i血液分析仪测定结果的影响.方法:观察不同温度、不同时间保存的血标本白细胞(WBC)、红细胞(RBC)、血红蛋白(HGB)、红细胞压积(HCT),平均红细胞体积(MCV)、血小板(PLT)和平均血小板体积(MPV)的变化.结果:4℃条件下保存的血标本,WBC、RBC、HGB、HCT、MCV和PLT的测定值在24h内无明显变化; MPV 8h内无明显变化,8h后升高.22℃和32℃条件下保存的血标本,WBC、RBC、HGB、HCT、MCV和PLT的测定值在12h(22℃)和6 h(32℃)内无明显变化; MPV的测定值在6 h(22℃)和4 h(32℃)内无明显变化,6h后(22℃)和4h后(32℃)明显升高,尤以32℃显著.白细胞散点图和白细胞分类在12 h时(4℃)、8 h时(22℃)和4 h时(32℃)开始发生变化.结论:抗凝血标本保存的最佳温度为4℃,22℃(室温)保存的标本应在8 h内完成检测;如果室温大于32℃,血标本采集后应在4h内完成检测.     

Effect of four organochlorine pesticides on the reproduction of freshwater rotifer Brachionus calyciflorus Pallas

Effects of four organochlorine pesticides, including dichlorodiphenyltrichloroethane (DDT), dicofol, endosulfan, and lindane, on the reproduction of freshwater rotifer Brachionus calyciflorus were studied by 3-d population growth tests. Compared to the control, dichlorodiphenyltrichloroethane at 0.64 mg/L, dicofol at 0.8 and 1.2 mg/L, endosulfan at 7.0 mg/L, and lindane at 14.0 mg/L all significantly decreased the population growth rate of the rotifers. Dichlorodiphenyltrichloroethane at concentrations higher than 0.16 mg/L, dicofol at concentrations higher than 0.025 mg/L, endosulfan at concentrations higher than 0.875 mg/L, and lindane at 14.0 mg/L all significantly decreased the mictic rate of the rotifers. Dichlorodiphenyltrichloroethane at 0.24 and 0.32 mg/L increased significantly the fertilization rate, but DDT at 0.64 mg/L inhibited completely the occurrence of fertilized mictic females. Dichlorodiphenyltrichloroethane at 0.32 and 0.64 mg/L, dicofol at 1.2 mg/L, and endosulfan at 7.0 mg/L all significantly decreased the ratio of ovigerous females to nonovigerous females, but the reverse was true for lindane at 7.0 mg/L. Dichlorodiphenyltrichloroethane at 0.0025 and 0.01 mg/L increased significantly the ratio of mictic females to amictic females, but the reverse was true for dicofol at 0.8 mg/L. Both population growth rate and mictic rate of the rotifers were suitable endpoints for assessing the effects of the four organochlorine insecticides on the reproduction of the rotifers, and the latter was more sensitive.     

Smoking patterns at a British and at an American medical school

Cigarette smoking among medical students at the University of Bristol (Bristol) and the New York University School of Medicine (NYU) was investigated and differences were subjected to statistical analysis.
At Bristol 34–6% and at NYU 14–3% of respondents classified themselves as regular smokers. Among students in the pre-clinical phase of training the difference between the number of smokers at Bristol and at NYU was not significant. At both schools more clinical students smoked than preclinical students, but only at Bristol did the difference between the number of smokers in the two grade levels reach statistical significance.
There are fewer heavy smokers (consumers of more than twenty cigarettes per day) among the pre-clinical students at Bristol than among preclinicals at NYU. In the clinical year, however, there were slightly (insignificantly) fewer heavy smokers at NYU while there were significantly more at Bristol.
Smokers at NYU acquired the habit at a somewhat earlier age than the smokers at Bristol.
The majority of students at both schools indicated that medical education had not influenced their decision to smoke or not to smoke.
Most smokers—more among the clinical than the pre-clinical students—reported that they were displeased with their habit and that they wished to give it up. Somewhat fewer smokers at Bristol gave that response than students at NYU.
Factors contributing, at least in part, to the differences between smoking patterns observed may be variables of age and years of education.
The widely held but untested belief that precept and example by medical school teachers may be a potent force for modifying the smoking behaviour of health professionals, is in need of research.     

In vivo and in vitro assessment of the sensitivity of Plasmodium falciparum to chloroquine in four districts of Tanga region, Tanzania

The sensitivity of Plasmodium falciparum to chloroquine was tested in Muheza, Pangani, Tanga and Korogwe districts in north-eastern Tanzania by applying both in vivo and in vitro tests in schoolchildren. A total dose of 25 mg chloroquine base/kg body-weight given over a period of three days (10 mg/kg on days 0 and one; and 5 mg/kg on day 2) failed to clear asexual parasites from the peripheral blood by day 7 in 12.5% of the children tested at Muheza, 5.9% at Pangani, 31.8% at Tanga, and 39.5% at Korogwe. In vitro micro tests were successfully carried out on 44 isolates at Muheza, 29 isolates at Pangani, 45 isolates at Tanga and 44 isolates at Korogwe. Schizont maturation at chloroquine concentrations of 1.14 mu mol/litre of blood and above, an indication of drug resistance, was observed in 20.5% of the isolates at Muheza, 41.4% at Pangani, 51.1% at Tanga and 45.5% at Korogwe. In vivo and in vitro results of the tests for resistance have been compared.     

Adolescence as possible critical temporal window for blood pressure short term monitoring in boys and girls

Adolescence is a critical temporal window for the development of obesity in adult age. We studied this period for short-term monitoring of blood pressure in both genders. Weight, height, body mass index (BMI), systolic and diastolic blood pressure (SBP, DBP) were recorded in 937 adolescents, 474 boys and 463 girls aged 12 years, and again 2 years later in the same subjects. Boys with BP values ≥95th percentile at both ages (no.=8) showed at 12 years weight (kg 61.4) height (cm 159.5) and BMI (23.5), and also at 14 years (77.0, 172.4, 25.6) values consistently higher than boys with high BP values at either ages taken singularly (no.=32 + 32) (mean 49.2, 154.4, 21.5, respectively, at 12 years, and 62.1, 167.0, 22.2 at 14 years). These 64 boys, had values higher than boys with BP always below the 95th percentile (no.=402) (45.5, 151.4, 19.7 at 12 years, and 56.9, 164.6, 20.9 at 14 years). This was confirmed for weight and BMI in girls. Stepwise logistic regression revealed that weight at 12 years and high BP values at 12 years were predictive independent risk factors for hypertension at 14 years. Odds ratio indicated that increment of body weight unit (1 kg) at 12 years predicted an average increase of 4 of risk for high BP values at 14 years, while high BP values at 12 years was predictive for a 2.19 times risk for high BP values at 14 years. Body weight, BMI and BP at 12 years of age may give useful indications for the prevision (and possible prevention) of hypertension and overweight at 14 years of age.     

动态监测STAT3、HMGB1在急性肝衰竭大鼠中的变化及意义

目的 观察信号转导子和转录激活因子(STAT3),高迁移率族蛋白B1(HMGB1)在D-氨基半乳糖介导急性肝衰竭模型中的动态变化规律.方法 用D-氨基半乳糖制作大鼠急性肝衰竭模型,用RT-PCR检测STAT3 mRNA,HNCB1 mRNA在急性肝衰竭大鼠肝组织6、12、24、48、72、120和168 h的表达.结果 STAT3 mRNA在急性肝衰竭的6 h有显著升高,与正常组差异有统计学意义(P<0.01),24 h达高峰,在48、72、120 h仍保持较高水平,与正常组比较差异有统计学意义(P<0.01);HMGB1 mRNA在6 h亦显著升高,与正常组比较差异有统计学意义(P<0.01),12 h达高峰,在24、48、72 h仍保持较高水平,与正常组比较差异有统计学意义(P<0.01).ALT和AST在6 h有轻度升高,至24 h与正常组差异有统计学意义(P<0.05),48 h(P<0.01)达高峰,72 h逐渐下降.TBil在6 h开始持续升高,72 h达到高峰(P<0.01),120 h逐渐下降.结论 STAT3、HNGB1可能参与了急性肝衰竭的病理生理过程,可能成为l临床上治疗急性肝衰竭的新靶点.     

Effects of pH on the toxicity and uptake of [14C]lindane in the midge, Chironomus riparius

The toxicity of the insecticide, lindane, was measured in the midge, Chironomus riparius, at pH 4, 6, and 8 with the finding that lindane is significantly more toxic at pH 6 than at pH 4 and 8. The higher toxicity of lindane at pH 6 is a product of two factors. First the penetration of the compound into the midge is lower at pH 4 than at pH 6 and 8. Second, a greater percentage of total radioactivity is contributed by parent compound at pH 6.     

Family social class, maternal body mass index, childhood body mass index, and age at menarche as predictors of adult obesity

BACKGROUND: Obesity is an increasingly prevalent nutritional disorder throughout the world and is a risk factor for many chronic diseases. The prevalence of obesity increases with age. OBJECTIVE: The objective was to evaluate the associations between BMI at 31 y of age and family social class during early childhood, maternal body mass index (BMI) before pregnancy, BMI at birth and at 1 and 14 y of age, and age at menarche. DESIGN: This was a longitudinal study of the northern Finland birth cohort for 1966. Subjects were measured at birth and at 1, 14, and 31 y of age. The analysis was restricted to individuals for whom BMI data were available for all measurement points (n = 2876 males and 3404 females). RESULTS: The mean BMI at birth was highest in offspring from the highest social classes, but BMI was inversely related to social class at 1 y. BMI, the waist-to-hip ratio, and the proportion of obese subjects were inversely related to social class at 31 y. The heavier the mother, the heavier the offspring from birth to 31 y. The paired analyses between maternal BMI and daughter's BMI at 31 y showed no significant difference in BMI after adjustment for the age difference. BMI at 14 y was the most important predictor of BMI at 31 y. Early menarche in females was associated with a higher BMI at 14 and 31 y. CONCLUSIONS: Differences in BMI by social class are formed at least partly during early childhood. Low social class of the child's family, a high maternal BMI before pregnancy, a high BMI during adolescence, and early menarche are predictors of obesity in adulthood.     

2011年地级城市医院与县级医院竞争力百强分析——新医改中地级城市医院竞争力状况报告(一)

在市管县背景下,县医院和地级城市医院在同一个地区发展,不可避免产生合作、竞争。要了解中国医院的生存、发展状态,数量最多、分布最广的县医院、地级城市医院是必须关注的重点。2011年地级城市医院与县级医院竞争力的对比分析显示,地级城市医院之间的竞争激烈程度超过县级医院,地级城市医院与县级医院在发展上各有其长处。     

Effect of pH on the toxicity of nickel and other divalent metals to Burkholderia cepacia PR1(301)

Nickel (Ni) is a common cocontaminant at many waste sites where the soils and sediments often are acidic, thereby influencing metal availability. Growth of Burkholderia cepacia PR1(301) was not affected at 3.41 mM Ni at pH 5, but was inhibited by 73.2% at pH 6 and inhibited completely at pH 7 compared to growth without Ni. This pH effect was not observed in the Ni-resistant strains, Ralstonia metallidurans CH34 and 31A. Predicted Ni speciation did not explain the observed toxicity trends. Sorption of Ni to PR1 increased with increasing pH (1.49, 1.12, and 3.88 mg Ni/g dry weight at pH 5, 6, and 7, respectively), but was low at all three pH values, and most likely does not explain the observed pH effect. Growth inhibition of PRI with increasing pH also was observed for other divalent cations, with growth observed at 4.24 mM Co, 2.22 mM Cd, and 3.82 mM Zn at pH 5 and 6, but totally inhibited at pH 7. These studies suggest that, at circumneutral pH, PRI would be considered sensitive to Ni and other divalent cations, in spite of the ability to grow in higher concentrations at lower pH values.     

The association between perineal trauma and spontaneous perineal tears

OBJECTIVE: We assessed whether women who had a perineal trauma (episiotomy or spontaneous tear of the second degree or higher) at the first delivery were at increased risk for spontaneous perineal tears at the next delivery, and whether the risk increases with the severity of previous perineal trauma. DESIGN: Retrospective cohort study. POPULATION: We included data from 1895 women who had their first and second deliveries at Saint-Sacrement Hospital, Quebec City, Canada, between 1985 and 1994. Our study was restricted to women who gave birth vaginally to a single living neonate at their first 2 deliveries and who did not have an episiotomy at the second delivery. We extracted the data from the Department of Obstetrics computerized database. OUTCOMES MEASURED: Spontaneous perineal tears (of second degree or higher) at the second delivery. RESULTS: Having a perineal trauma at the first delivery more than tripled the risk (relative risk=3.3; 95% confidence interval, 2.6-4.2) of spontaneous perineal tears at the second delivery. The risk of spontaneous perineal tears at the second delivery increased with the severity of previous perineal trauma at birth. CONCLUSIONS: Our results show that the risk of spontaneous perineal tears at subsequent deliveries increases with the presence and the severity of perineal trauma at the first delivery.     

Zinc and copper concentrations in breast milk and maternal serum in the postpartum period

This study reports the contents of Zn and Cu in the breast milk and serum of postpartum mothers, 17 primiparas and 20 multiparas, at one week and at one month after delivery. Results were as follows. 1. The mean content of Zn in the breast milk was 5.44 micrograms/ml at 1 week after delivery, and it decreased significantly (p less than 0.01) to 2.73 micrograms/ml at 1 month after delivery. 2. The mean content of Zn in serum was 0.66 microgram/ml at 1 week, and it increased significantly (p less than 0.01) to 0.84 microgram/ml, close to the normal level, at 1 month. 3. The milk Zn level at 1 week after delivery was about 8 times as high as the Zn in serum. There was a significant (p less than 0.05) negative correlation in Zn contents between milk and serum at 1 week after delivery, and there was no significant correlation in Zn contents between milk and serum at 1 month after delivery. 4. The mean content of Cu in breast milk was 0.55 microgram/ml at 1 week after delivery, and it decreased to 0.44 microgram/ml at 1 month after delivery. 5. The mean content of Cu in serum was 2.14 micrograms/ml at 1 week after delivery, and it decreased significantly (p less than 0.01) to 1.35 micrograms/ml, close to the normal level, at 1 month after delivery. 6. Concerning the Cu contents of milk and serum, there was not a significant correlation at 1 week after delivery, but a significant (p less than 0.05) positive correlation was found at 1 month after delivery.     

安徽省农民工艾滋病传播材料开发和使用活动及其效果评价

目的针对安徽省农民工开发艾滋病健康传播材料并开展艾滋病健康教育活动,提高农民工艾滋病相关知识知晓率：方法采用社区干预方法,根据需求评估结果,开发传播材料,设计和开展健康教育活动配合材料使用,并对效果进行评估。结果干预前后调查对象艾滋病基本知识知晓率分别为62．6％和86．7％（P〈0．001）。干预前后无偿献血知识知晓率分别是48．6％和78．2％（P〈0．001）。干预后两个知晓率均达到了《中国遏制艾滋病行动计划（2006～2010）》的目标。于预前后艾滋病自愿咨淘检测（VCT）服务的知晓率分别为46．3％和74．8％（P〈0．001）：干预前后农民工艾滋病防治相关正确态度符合率分别是736％和85．0％（P〈0．001）。干预前后接受VCT服务的比例分别是16．0％和36．2％（P〈0．001）．自报有婚外（婚前）性行为的比例在于预前后分别为26．8％和20．1％（P=0．066）。最近3次与婚外（婚前）性伴的性行为中均使用安全套的比例在干预前后分别为11.8%和16．4%（P=0．458）。结论针对农民工开发和利用艾滋病健康传播材料有效地提高了集中场所农民工的艾滋病防治相关知识和正确态度,改善了VCT服务的利用行为．但对危除性行为的改变效果不明显。     

Temperature effects on fruit quality of mature green tomatoes during controlled atmosphere storage

Tomatoes were harvested at the mature green stage of maturity and stored at 13 degrees C and 15 degrees C for 60 days at three different combinations of CO(2), all with 5.5% O(2) compared with a control with 20.9% O(2) with 0.3% O(2)/% CO(2). Tomatoes were evaluated for changes in colour, titratable acidity, total soluble solids and decay appearance. In this experiment, the 'Criterium' variety of tomatoes was used and it was found that this variety was not suitable for storage at 13 degrees C. Some chilling injury symptoms were observed during the storage period at 13 degrees C, which did not occur at 15 degrees C. Uneven colour development, irregular changes in titratable acidity and total soluble solids were observed during the storage period at 13 degrees C, and the fruits did not ripen properly even after further 10 days ripening time in air at 20 degrees C. Furthermore, the amount of decayed fruits was higher at 13 degrees C than at 15 degrees C, especially after 50 days of storage. In fruits stored for 60 days at 13 degrees C, alterneria rot, blue mould rot and 'cottony leak' occurred that could be associated with chilling injury and increased during a further 10 days ripening at 20 degrees C. It was concluded that the 'Criterium' variety is not suitable for storage at 13 degrees C.     

Optimal daytime feeding regimen to prevent postprandial hypoglycemia in type 1 glycogen storage disease.

To determine the optimal daytime dietary regimen for type 1 glycogen storage disease (GSD), we used uncooked cornstarch (UCS) at a basal glucose production rate (GPR) in single and divided doses, with mixed meals at 0700 and 1700 h. This regimen was compared with a 1.5 times larger single dose of UCS at 0700 h, and with dextrose at GPR at 1200 h. Two-hour UCS loads (amount equal to GPR in 2 h) given with a mixed meal at 0700 h and 180 min later maintained mean blood glucose (BG) concentrations at greater than or equal to 4.2 mmol/L for 300 min. BG was significantly greater from 240 to 300 min compared with a single 4-h UCS load, and at 300 min compared with a single 6-h UCS load. Similar effects were noted when the divided UCS regimen was given with a mixed meal at 1700 h, but not when isoenergetic amounts of dextrose were given on the same schedules with a mixed meal at 1200 h. A daytime schedule of six UCS feedings (with the three main meals and 180 min later) at GPR maintains BG at concentrations that should minimize biochemical abnormalities and optimize clinical outcome in patients with GSD.     

Early menopause, number of reproductive years, and bone mineral density in postmenopausal women.

OBJECTIVES. Previous studies have reported positive associations of age at menopause with bone density and inverse associations of age at menarche with bone density. This study examined the relationships of early age at menopause and number of reproductive years (defined as age at menopause minus age at menarche) with bone density in postmenopausal women. METHODS. The subjects were 555 women aged 60 to 89 years who had had either natural menopause (n = 391) or hysterectomy with bilateral oophorectomy (n = 164). Bone density was measured at the ultradistal wrist, midshaft radius, lumbar spine, and hip. RESULTS. Women who had had early menopause and those with the fewest reproductive years had significantly lower bone density at all sites. After adjustment for covariates, both age at menopause and number of reproductive years had significant positive associations with bone density at every site, and total number of reproductive years explained more of the variance in bone mineral density than did either age at menarche or age at menopause. CONCLUSIONS. Elderly women reporting early menopause or fewer reproductive years have more osteoporosis. The number of reproductive years may be more helpful than age at menopause in identifying women at increased risk of osteoporosis.     

VEGF在局灶性脑缺血大鼠中表达规律的研究

目的探讨局灶性脑缺血大鼠模型中血管内皮生长因子（Vascular Endochelial Growth Factor,VEGF）的表达规律。方法制备大鼠局灶性脑缺血再灌注模型（Middle Cerebral Artery Occlusion,MCAO）,随机将实验大鼠分为两组：假手术（SH）组和手术（OP）组,OP组又分为再灌注6 h,12 h,1 d,3 d,7 d,14 d六个时间点。采用神经功能评分、TTC染色、光镜检测方法对模型予以评价。采用免疫组化技术观察再灌注不同时间点脑梗塞中心区及半影区VEGF及F8因子表达变化情况。结果 SH组无VEGF表达,OP组梗塞中心及半影区VEGF 6 h有表达,3 d达高峰期,7d后下降;而表达VEGF的新生血管内皮细胞3 d开始明显增多,7 d达高峰,14 d后下降。OP组F8因子（各大文献中均无F8因子的中文名字）在梗塞中心及半影区表达24 h开始减少并进行性下降,7 d周边区表达开始增加,14 d持续增多。结论 MCAO大鼠梗塞中心及半影区VEGF表达3 d达高峰期,7 d开始下降,而新生血管内皮细胞阳性表达出现晚,7 d达高峰;F8表达7 d开始增加,14 d持续增多。     

A little planning goes a long way: multilevel allocation of HIV prevention resources.

BACKGROUND: HIV prevention funds are often allocated by decision makers at multiple levels. High-level decision makers may allocate funds to regions, and regional decision makers then allocate those funds to specific programs. Often, funds are allocated proportionally (e.g., in proportion to HIV incidence) rather than efficiently (i.e., to maximize HIV infections averted). The authors investigate the impact of efficient and proportional allocation methods at 2 different decision levels. METHODS: The authors developed an optimization model of resource allocation at 2 levels-an aggregate upper level and multiple local levels-and considered efficient allocation and allocation proportional to HIV incidence. Using data from 40 U.S. states, they compared 4 strategies for allocating HIV prevention funds. RESULTS: The greatest health benefit (HIV infections averted) occurred when efficient allocations were made at both levels. When funds were allocated proportionally at the higher level and efficiently at the lower level, the health benefit was about 5% less than when efficient allocations were made at both levels. When funds were allocated efficiently at the higher level and proportionally at the lower level, the health benefit was 15% less than when efficient allocations were made at both levels. The least health benefit (23% less than when efficient allocations were made at both levels) occurred with proportional allocation at both levels. CONCLUSIONS: Efficient allocation only at the higher level cannot overcome poor allocations at lower levels. Moreover, efficient allocation at the lower level is likely to yield greater gains than efficient allocation at the higher level. Thus, upper-level decision makers, such as donor organizations, should develop incentives to promote efficient allocation by lower-level decision makers.